Answer:
In homeothermic (“warm-blooded”) animals, body temperature is carefully
regulated. The hypothalamus, located in the brain, acts as the master ther-
mostat to keep body temperature constant to within a fraction of a degree
Celsius in a healthy animal. If the body temperature starts to deviate much
from the desired constant level, the hypothalamus causes changes in blood
flow and initiates other processes, such as shivering or perspiration, to bring
the temperature back to normal. What evolutionary advantage does a con-
stant body temperature give the homeotherms (e.g., birds and mammals)
over the poikilotherms (e.g., reptiles and insects), whose body temperatures
are not kept constant? What are the disadvantages?
Explanation: Basic chemical understanding as revealed upwards